Fire extinguishing system



Jan. 30, 1951 D. MAPEs 2,539,452

FIRE EXTINGUISHING SYSTEM Filed May 26, 1944 2 Sheets-Sheet l 31 lgINYEI %K%d at W ATT RNEY Jan. 30, 1951 D. MAPES 2,539,452

FIRE EXTINGUISHING SYSTEM Filed May 26, 1944 2 Sheets-Sheet 2 L zw%z u AORNEY Patented Jan. 30, 1951 FIRE EXTINGUISHING SYSTEM Daniel Manes,West Caldwell, N. l, assignor to Specialties Development Corporation,Bloomfield, N. 3., a corporation of New Jersey Application May 26, 1944,Serial No. 537,494

9 Claims.

My invention relates to fire extinguishing and more particularly to asystem for extinguishing fires occurring in enclosures and the like. I

My invention is particularly concerned with extinguishing fires inenclosures such as cargo holds, storage spaces, tanks, rooms orcompartments, and the casings or ho' sings of electrical equipment orinternal combustion motors. Usually, an inert fire extinguishing m diumsuch as carbon dioxide, nitrogen, or mixtures thereof, or any suitablefluid pressure fire extinguishing medium is introduced into theenclosure to establish an inert atmosphere in which combustion cannottake place.

Heretofore it has been customary to extinguish fires in such enclosuresby introducing a predetermined quantity of the medium. Usually, thequantity was controlled by emptying a container of fire extinguishingmedium of predetermined capacity into an enclosure of a given volume.This required using the entire contents of the container even if only asmall portion thereof would have been sufiicient to extinguish the fire.In the event the fire reignited itself after the introduction ofthe'fire extinguishing medium into the enclosure, the second fire couldnot be extinguished unless a reserve supply of fire extinguishing mediumwas provided for. The requirement of a reserve su ply resulted in theincrease in size and weight of the systems required to protect anenclosure or group of en"- closures and resulted in more complexconnectib'ns and controls for operating the system.

My invention aims to provide a system for extinguishing fires inenclosures wherein. initially,

the fire extinguishing medium is introduced into the enclosure until anatmosphere of predetermined inertness has been established to extinguishthe fire, and, thereafter, an additional uuaiitity of the medium isintroduced into the enclosure in response to a decrease in the inertnessof the atmosphere in the enclosure toprevent a reoccur'rence of the fireduring a fire period, thereby conserving the fire extinguishing mediumover a period during which the me may reoccur.

Accordingly, an object of my invention is to provide 'a fireextinguishing system which elimi- 'nat'e's the waste of fireextinguishing medium.

Another object is to provide a fire extinguishing system adapted tomaintain an inert atmos- "phere in an enclosure for a considerableperiod "after the commencementof fire to prevent the 'r'eoccurrenee of al fire during the fire period.

Another object isto provide a fire extinguish 2 ing system of theforegoing character wherein the release of additional fire extinguishingmedium, after an initial discharge, is controlled by the inertness ofthe atmosphere in the enclosure protected.

Another object is to provide a system which is simple in constructionand can effectively control fires in enclosures with a minimum amount offire extinguishing medium.

A further object is to provide a, system for extinguishing fires whichis reliable, effective and safe.

Other and further objects of the invention will be obvious unon anunderstanding of the illustrative embodiment about to be described, orwill be indicated in the appended claims, and various advantages notreferred to herein will occur to one skilled in the art upon employmentof the invention in practice.

A preferred embodiment of the invention has been chosen for purposes ofillustration and description and is shown in the accompanying drawings,forming a part of the specification, where- Figure 1 is a diagrammaticview of afire extinguishing system, illustrating an embodiment of myinvention.

Figure 2 is a diagrammatic view of a control circuit used in connectionwith the system.

As illustrated in Figure l of the drawings, I provide a container '5 inwhich is stored any suitable inert fiuid pressure fire extinguishingmedium, for instance, liquefied carbon dioxide. The container isprovided with a control head 6 operable for releasing the medium to anenclosure 1 by means of a conduit 8 which has one end connected to thecontrol head 6 and the other end equipped with a discharge head or horn9 disposed within the enclosure 1. I,

While the enclosure is illustrated by way of example as a compartment,it will be understood that it is intended to represent diagrammaticallyany of the spaces or enclosures referred to herein.

The conduit 8 has incorporated therein a control device ill forcontrolling the introduction of the medium to the enclosure and whichdevice comprises a normally open solenoid con-- trolled valve connectedin an electric circuit controlled by an analyzer l3 for measuring the in'ertness of the atmos here in the enclosure 1. This may be accomplishedby testing the atmosphere to determine if it will support combustion,

or, for example, by measuring percentage of carbon dioxide in theatmosphere within the enclosure 1.

The latter may be accomplished by observing the thermal conductivity ofthe atmosphere. The value of the conductivity of a gas may beascertained when compared with air, the observed or computed ratio thusestablished being deemed the factor of thermal conductivity of gas. Thethermal conductivity factor of carbon dioxide gas is such that it lendsitself to the thermal conductivity test in such a manner that the actualpercentage of carbon dioxide present in the air of an enclosure can besubstant ally directly observed and registered on a galvanometer bymeans of a Wheatstone bridge arrangement.

The procedure in and the apparatus used for making observations of theforegoing described character is well known in the art and a detaileddescription thereof is not deemed necessary, it be ng sufficient todisclose the analyzer l3 (Figure 2) as comprising an unba ancedWheatstone bridge M which has connected thereto wires i 5 and iii in acircuit with a source ll of a constant E. M. F., the wire 16, adjacentthe source I I having incorporated therein a switch l8 operated to cosed posit on when the control head is actuated for releasing the fluidfrom the container.

One pair of the arms of the bridge are formed by the fixed resistancesI3, whereas the other pair of the arms contain the resistance wires ofthermal conductivity units 20 and 2|. A galvanometer 22 is connectedacross the bridge as an indicating instrument by means of wires 23 and24. The thermal conductivity unit 20 is bridged by a suitable resistancewire and it contains a com arison gas, whereas the thermal conductivityunit 2|, which is equipped with a similar resistance wire, has its inletconnected to a relatively small pipe 25 leading to the enclosure 1whereby air from the enclosure is supplied for ana ysis. Alternat vely,the unit 2| could be located in the enclosure and connected electricallyin the bridge circuit.

The outlet of the unit 2| is connected to a pipe 26 leading to a pump 21or the like, the pump being operated in any suitable manner, forinstance, by a pressure operated motor 28 connected to the conduit 8,between the control dev ce Ill and the control head 6, by a pipe 29having a pressure re u ating va ve 3!] incorporated therein. A pipe 3|connects the motor 28 to the enclosure '1 whereby the pressure mediumpassing therethrough is introduced into the enclosure. The analyzed airafter passing through the pump may be conducted by a pipe 52 to asuitable location where the air may be visually observed to determine,for example, the smokiness thereof.

The galvanometer 22 is empirically calibrated and is provided with ahand or pointer 32 adjacent a scale 33 reading from 0 to 100 to denote.bon dioxide is in the enclosure to therebyv efiect operation of thecontrol device I 0 to shut off the flow of carbon diox de to theenclosure.

The brush 34 of the hand 32 is connected to one pole of the E. M. F. bya wire 36 connected to the wire l6 while the segment 35 is connected toa magnet 3'! of a relay 39 by means of a wire 43, and the magnet isconnected to the other pole of the battery by means of a wire 43connected to the wire l5. The relay 39 is provided with an armature inthe form of a pivoted lever 44 which constitutes a switch element of aswitch 45. The pivoted end of the lever 44 is connected to the wire 43and the free end of the lever is adapted to engage a contact connectedby a wire 46 to one terminal of the solenoid of the control device in,the other terminal of the solenoid be ing connected to the wire I6 bymeans of a wire 47. The lever 44 is held out of attracted position withthe magnet 3'! by means of a spring 48.

When the carbon dioxide concentration exceeds 35%, the brush 34 willengage the segment 35 thereby energizing the magnet 31 and operating theswitch into closed position to energize the solenoid of the controldevice It], whereby the normally open valve of the control device willbe closed. 'When the percentage of carbon diox de in the enclosure isless than 35%, the brush 34 is out of engagement with the segment 35 andthus the magnet 37 is not energized. The switch 45 is then in openposition and the so enoid of the control device Ill is not energized,thereby enabling the valve of the control device it. to open and admitcarbon dioxide to the enclosure.

If desired, an alarm or signal 50 may be provided which is actuated whenthe carbon dioxide concentration falls below 35%. The alarm is connectedin a circuit comprising a wire, connected to one side of thesource of E.M. F. I! and to the s gnal 53, a wire 6| connected to the signal and toan arcuate segment 53 position on the scale along the 0 to 35% zone. Thebrush 34 of the hand is adapted to engage the segment 53 and establishan electrical connection with the other side of the source of E. M. F.I! by way of the wires 36 and I6, and the switch l8. The alarm may bedisconnected by opening a switch 5! in the wire 3!. It will beunderstood that, in practice, the brush and segment switch arrangementwould be arranged to operate a relay which in turn would close thesignal circuit.

The cont ol head 3 may be o erated manually or automaticallv in anysuitable manner. For example, a solenoid 7i] mav be provided for thispurpose which is connected in an electrical circuit ada ted to be closedupon o eration of a heat responsive switch element H located in theenclosure. The heat responsive element ll may be of the tvne disclosedin United States Patent No. 2,318,607.

In operation, the occurrence of a fire in the enclosure 1 may bedetected visually or by any suitable alarm or for example by the heatresponsive switch ll which automatically effects operation of the deviceill for operating the discharge control head 6 adapted to release thecarbon dioxide into the conduit 8 which conducts it past the normallopen valve I3 and into the enclosure. The operation of the control head6 effects closing of the switch l8 which puts the analyzer intooperation. Carbon dioxide continues to be discharged into the enclosureuntil a desired or predetermined concentration of carbon dioxide isestablished whereupon the analyzer circuit is eiiective to cause thevalve ill to be clo ed. a

The analyzer continues to test the carbon di oxide concentration duringthis period, and, in the event the concentration should drop below apredetermined value, the valve H] is reopened to permit an additionalquantity of carbon dioxide to be introduced into the enclosure. Theforegoing may be repeated until it has been definitely established thatthe fire has been completely extinguished and that reoccurrence thereofis not probable.

In order to more fully understand some of the practical aspects of myinvention, the operation of the system will be described in connectionwith several different types of enclosures chosen by way of example. 7

As previously indicated, the enclosure l may be a compartment, hatch orstorage space wherein is stored any material constituting a class A(ordinary combustible materials) or a class B (highly inflammablematerials) type fire hazard. Should a fire occur due to negligence,spontaneous combustion or other causes, the system is operated asdescribed above. Should the fire rekindle itself due to glowing embersor heat remaining in the material after the carbon dioxide concentrationhas dropped, additional carbon dioxide is introduced into the space.This may be repeated until the compartment can be entered and inspectedto determine the cause of the fire and elfect the removal of the cause.

Another advantageous use of my invention is in connection with internalcombust on m tors of aircraft, for example. Should a fire occur, it isextinguished by the initial discharge of carbon dioxide while thereaftermaintaining a carbon dioxide concentration in the engine nacelle toprevent or extinguish further fires. This particularly advantageousbecause it permits the engine to be kept in operation until an emergencylanding can be made. Also, in connection with multi-motored aircraft itis desirable to maintain a faulty engine partly in operation instead ofcutting it out completely. For example, even if the fire-plagued enginecan be operated at a very low speed to permit the propeller to rotate,the air resistance to the craft is materiallv decreased and theremaining engines are not subjected to excessive strains.

My invention also may be utilized in connection with electrical fires(class C) which, for example, may occur in motors or generators due tofaulty or worn out insulation. In the event a fire occurs, the system isoperated to extinguish the fire and thereafter is operatedintermittently to maintain an inert atmo phere in the casing or housingto prevent or extinguish further fires.

This enables the equipment to be used at least until there is anopportunity to shut down the equipment and repair the same. I

From the foregoing, it will be apparent that my invention provides anapparatus whereby a fluid medium, for instance, carbon dioxide, may beintroduced into an enclosure and maintained therein over an appreciableperiod of time and with a substantially uniform qxmcentration valueduring such time. While I have described my invention in connection withthe utilization of carbon dioxide, it is to be distinctly understoodthat any other suitable fluid medium may be employed for a like orsimilar purpose.

As various changes may be made in the form, construction and arrangementof the parts herein, without departing from the spirit and scope of theinvention and without sacrificing any of its advantages, it is to beunderstood that all matter herein is to be interpreted as illustrativeand not in any limiting sense.

It is also to be understood that the following cIaimsare intended tocover all the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention, which, as amatter of language, might be said to fall therebetween.

I claim:

1. In combination with an enclosure wherein the atmosphere normally issuificient to support combustion, a fire extinguishing system comprisinga source of supply of fire extinguishing gas, means for con-ducting gasfrom said source into said enclosure upon the outbreak of fire thereinin sufficient quantity to extinguish the fire, means rendered effectiveupon the outbreak of fire in said enclosure and operable thereafter fordetermining the concentration of the fire extinguishing gas in theenclosure, and means controlled by said determining means formaintaining a concentration of the fire extinguishing gas in saidenclosure sufficient to prevent recurrence of the fire.

2. In combination with an enclosure wherein the atmosphere normally issufficient to support combustion, a fire extinguishing system comprisinga source of supply of fire extinguishing gas, means responsive to theoutbreak of fire in the enclosure, means for releasing the gas from saidsource actuated upon operation of said responsive means, means forconducting the released gas from said source into said enclosure insufiicient quantity to extinguish the fire, means operable thereafterfor analyzing the atmosphere in the enclosure, means operable upon theoperation of said releasing means to render said analyzing meansefiective, and means controlled by said analyzing means for alternatelydiscontinuing and'resin. ng the flow of the gas from said source intosaid enclosure when the analysis of the atmosphere therein indicates afire extinguishing gas concentration sufiicient and insufficient, re-

spectively, to prevent recurrence of the fire.

'maintaining an atmosphere therein incapable of supporting combustion,the combination of a container for supplying a fire extinguishing gas,conduit means for conveying the gas from the container into theenclosure, release means for releasing the gas from the container tosaid conduit means, an analyzer for ascertaining the concentration ofthe gas in the enclosure when mixed with air therein, means operableupon operation of said release means to render said analyzer effective,and control means in said conduit means operable by said analyzer tocontrol the admission of gas into the enclosure after extinguishment ofthe fire to maintain a mixture of air and gas therein incapable ofsupporting combustion.

4. In an automatic system for extinguishing fire in an enclosed spacesubject to asupply of outside air, and thereafter maintaining anatmosphere therein incapable of supporting combustion, the combinationof a source of supply of fire extinguishing medium under pressure formixture with air in the enclosed space to render the mixture incapableof supporting combustion, means for releasing medium from said source,fire responsive means in the enclosure for actuating said releasingmeans upon the outbreak of fire in the enclosure, means for conducting"the released medium from the supply source into the space to extinguishthe fire, said last means including a normally open valve, means for'an-7 alyzing the mixture, means operable upon the operation of saidreleasing means to render said analyzing means efiective, and meanscontrolled by said analyzing means for closing and opening said valve inresponse to the analyzing means alternately to prevent and to cause flowof the medium into the space whereby to maintain the mixture incapableof supporting combustion.

5. In combination with an enclosure wherein the atmosphere normally issufiicient to support combustion, a fire extinguishing system comprisinga source of fire extinguishing gas, means for conducting the gas fromsaid source into the enclosure, a valve in said conducting means, meansfor withdrawing samples of the atmosphere within the enclosure includinga conduit, means associated with said conduit for analyzing the samplesand for controlling said valve, and gas operated motor means foroperating said sampling means including a conduit connected to saidconducting means.

6. In combination with an enclosure wherein the atmosphere normally issufficient to support combustion, a fire extinguishing system comprisinga source of fire extinguishing gas, means for conducting the gas fromsaid source into the enclosure, a valve in said conducting means, aconduit having one end extending into said enclosure, suction meansconnected to said conduit for withdrawing samples of the atmospherewithin the enclosure, means associated with said conduit for analyzingthe samples and controlling the valve, a pipe connected to saidconducting means between said valve and said source, and gas operatedmotor means connected to said pipe for operating said suction means.

'7. In combination with an enclosure wherein the atmosphere normally issufiicient to support combustion, a fire extinguishing system comprisinga source of fire extinguishing gas, means for conducting the gas fromsaid source into the enclosure, a valve in said conducting means, aconduit having one end extending into said enclosure, suction meansconnected to said conduit for withdrawing samples of the atmospherewithin the enclosure, means associated with said conduit for analyzingthe samples and controlling the valve, a pipe having one end connectedto said conducting means between said valve and said source and havingits other end extending into the enclosure, and gas operated motor meanshaving an inlet and an outlet connected to said pipe for operating saidsuction means.

8. In combination with an enclosure wherein the atmosphere normally issufficient to support 8 I combustion, a fire extinguishing systemcomprising a source of fire extinguishing gas, means for conducting thegas from said source into the enclosure, a valve in said conductingmeans, a conduit having one end extending into said enclosure, suctionmeans connected to said conduit for withdrawing samples of theatmosphere within the enclosure, means associated with said conduit foranalyzing the samples and controlling the valve, a pipe having one endconnected to said conducting means between said Valve and said sourceand having its other end extending into the enclosure, gas operatedmotor means having an inlet and an outlet connected to said pipe foroperating said suction means, and flow restricting means in said pipebetween said conducting means and said motor means.

9. In combination with an enclosure wherein the atmosphere normally issufiicient to support combustion, a fire extinguishing system comprisinga source of fire extinguishing gas having means for releasing the gastherefrom, means for conducting the gas from said source into theenclosure, a valve in said conducting means, a conduit having one endextending into said enclosure, suction means connected to said conduitfor withdrawing samples of the atmosphere within the enclosure, meansassociated with said conduit for analyzing the samples and controllingthe valve, means operable by said releasing means to render saidanalyzing means effective, a pipe having one end connected to saidconducting means between said valve and said source and having its otherend extending into the enclosure, gas operated motor means having aninlet and an outlet connected to said pipe for operating said suctionmeans, and flow restricting means in said pipe between said conductingmeans and said motor means.

DANIEL MAPES.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 7,269 Phillips Apr. 9, 1850910,036 Wolfson Jan. 19, 1909 1,244,427 Coppus Oct. 23, 1917 1,993,695Allen et a1. Mar. 5, 1935 2,025,782 Seat Dec. 31, 1935 2,265,810 Lowe eta1. Dec. 9, 1941 2,353,538 Barber July 11, 1944

